1. Field of the Invention
The present invention relates to an information generating apparatus, an information reproducing apparatus and an information record medium, which can protect that legally generated information is illegally copied and further illegally reproduced to be generally distributed.
2. Description of the Related Art
Video information such as a movie or the like and audio information such as a music or the like are protected by the copyrights in many cases. In these cases, it is basically prohibited to copy such information without a permission.
Moreover, an owner of the copyright needs to have a plan of effectively protecting the copy.
A method for applying to the video information or the like a modulation referred to as a xe2x80x9cscramblexe2x80x9d is typically employed as a method for protecting the illegal copy. This scramble modulation is a modulating method, the modulated information by which cannot be demodulated without special key data. Usually, the key data is recorded on a data record area in an optical disc or the like as record information (data to be recorded) together with the scramble-modulated video information, and then the optical disc or the like is sold.
By a user who buys the optical disc, only if the key data recorded in a reproducing device for the optical disc owned by the user coincides with the key data recorded together with the video information on the optical disc, the scramble-modulated video information can be demodulated in accordance with the key data to thereby reproduce the video information. At this time, as long as the user manages the key data to be unknown to other persons, even if only the scramble-modulated video information is illegally copied, this cannot be demodulated or reproduced.
However, in the above explained method for protecting the illegal copy, the key data is recorded on the data record area of the optical disc as the record information together with the scramble-modulated video information and the like. Thus, there may be a case in which the key data is illegally copied together with the video information and the like. This results in a problem that a person, who makes an illegal copy, may use the obtained key data to demodulate the scramble-modulated video information and the like so that he or she can view and hear it.
Moreover, in the above explained method for protecting the illegal copy, there is no technique to judge whether or not the video information or the like is legally distributed (i.e., whether or not the video information or the like is a so-called xe2x80x9coriginalxe2x80x9d). Hence, this results in a problem that even in a case of the illegally copied video information or the like, it is impossible to judge whether or not it is illegally copied.
The present invention is proposed in view of the above mentioned problems. It is therefore an object of the present invention to provide an information generating method and an information generating apparatus, an information reproducing method and an information reproducing apparatus, and an information record medium, which can protect legally generated video information, audio information or the like from being illegally copied and further illegally reproduced.
The above object of the present invention can be achieved by an information generating method of generating output information to be outputted. The information generating method is provided with: adding an error correction code, which is used for an error correction of the output information when the output information is outputted, to the output information to thereby generate the output information having the error correction code; and replacing a part of the output information having the error correction code, which is generated by the adding process, with identification information indicating that the output information to be outputted is not illegally copied to thereby generate the partially replaced output information.
According to the information generating method of the present invention, in the adding process, the error correction code is added to the output information, so that the output information having the error correction code is generated. Then, in the replacing process, the part of the output information having the error correction code is replaced with the identification information, so that the partially replaced output information is generated.
Thus, for example, when the generated partially replaced output information is recorded onto the information record medium such as a DVD or the like and then the output information is reproduced from the information record medium, by allowing the reproducing operation only when the identification information is detected, it is possible to protect the output information having no identification information (i.e., the illegally copied output information) from being illegally reproduced.
Moreover, since the part of the output information having the error correction code is replaced with the identification information after the error correction code is added, even if the identification information is detected and the output information is reproduced when the output information is reproduced for example, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus. Therefore, the information reproducing apparatus which can reproduce the output information only when the identification information is detected can protect the reproduction of the output information recorded by the information recording apparatus. Namely, it is possible to protect the output information from being illegally reproduced.
Furthermore, for example, assuming that the partially replaced output information is transmitted to another information reproducing apparatus and is reproduced thereby, if the reproducing operation is allowed only when the identification information is detected, even if the output information having no identification information is transmitted, its illegal reproduction can be protected.
Moreover, even if the identification information is detected and the output information is reproduced after the transmission, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus. Therefore, the information reproducing apparatus, which can reproduce the output information only when the identification information is detected, can protect the reproduction of the output information recorded by the information recording apparatus. Namely, it is possible to protect the output information from being illegally reproduced.
In one aspect of the information generating method of the present invention, the information generating method is further provided with the process of adding sub-identification information, which indicates that the output information is not illegally copied, to the output information. In the error correction code adding process, the error correction code is added to the output information to which the sub-identification information is added to thereby generate the output information having the error correction code and the sub-identification information. Assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by a following expression (1).
M=f(N)xe2x80x83xe2x80x83(1)
According to this aspect, in the sub-identification adding process, the sub-identification information is added to the output information. Then, in the error correction code adding:process, the error correction code is added to the output information to which the sub-identification information is added, so that the output information having the error correction code and the sub-identification information is generated. At this time, the sub-identification information M is a predetermined function of the identification information N.
Thus, for example, when the output information is reproduced from the information record medium, by allowing the reproducing operation only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, in the reproducing apparatus for reproducing the output information, it is possible to more effectively protect the output information, which has been illegally recorded, from being reproduced.
In another aspect of the information generating method of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol. In the replacing process, the part of the output information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other is replaced with the identification information.
According to this aspect, for example, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the output information itself at the time of reproducing the output information which has been recorded on the information record medium, is not replaced with the identification information. Thus, the error correction ability with respect to the output information itself is not degraded. Further, in the similar manner, at the time of reproducing the output information which has been transmitted, the error correction ability with respect to the output information itself is not degraded.
The above object of the present invention can be also achieved by a first information record medium on and from which record information is recorded and reproduced. The first information record medium is provided with: an error correction code recorded on the information record medium by adding the error correction code, which is used for an error correction of the record information when the record information is reproduced, to the record information to thereby generate the record information having the error correction code; and identification information recorded on the information record medium by replacing a part of the record information having the error correction code, with the identification information indicating that the record information to be reproduced is not illegally copied to thereby generate the partially replaced record information.
According to the first information record medium of the present invention, by replacing the part of the record information having the error correction code with the identification information, the partially replaced record information is recorded. Thus, by allowing the reproduction only when the identification is detected at the time of reproducing the partially replaced record information form the information record medium, it is possible to protect the record information, which does not have the identification information (i.e., which has been illegally copied), from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, even if the identification information is detected and the record information is reproduced, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded. Thus, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
In one aspect of the first information record medium of the present invention, the information record medium is further provided with sub-identification information recorded on the information record medium by adding the sub-identification information, which indicates that the record information is not illegally copied, to the record information in advance. The error correction code is recorded by adding the error correction code to the record information to which the sub-identification information is added to thereby generate the record information having the error correction code and the sub-identification information. Assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by the aforementioned expression (1) (i.e., M=f(N)).
According to this aspect, the output information having the error correction code and the sub-identification information is recorded on the information record medium, and that the sub-identification information M is a predetermined function of the identification information N.
Thus, for example, when the record information is reproduced from the information record medium, by allowing the reproducing operation only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, in the reproducing apparatus for reproducing the record information, it is possible to more effectively protect the record information, which has been illegally recorded, from being reproduced.
In another aspect of the first information record medium, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol. The part of the record information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other is replaced with the identification information.
According to this aspect, for example, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the record information itself at the time of reproducing the record information which has been recorded on the information record medium, is not replaced with the identification information. Thus, the error correction ability with respect to the record information itself is not degraded.
The above object of the present invention can be also achieved by a first information reproducing method of reproducing record information from the above described information record medium such as a DVD or the like of the present invention. The first information reproducing method is provided with the processes of: detecting the partially replaced record information from the information record medium; extracting the identification information from the partially replaced record information detected by the detecting process; judging whether or not the identification information is extracted by the extracting process; and reproducing the record information by applying the error correction to the partially replaced record information, which is detected by the detecting process, by use of the error correction code only if the identification information is judged to be extracted by the judging process.
According to the first information reproducing method, at first in the detecting process, the partially replaced record information is detected from the information record medium. Then, in the extracting process, the identification information is extracted from the partially replaced record information. Then, in the judging process, it is judged whether or not the identification information is extracted. Finally, in the reproducing process, only if the identification information is judged to be extracted, the record information is reproduced by applying the error correction to the partially replaced record information by use of the error correction code.
Therefore, since the reproduction can be performed only when the identification information is detected, it is possible to protect the record information having no identification information (i.e., the illegally copied record information) from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded. Therefore, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
The above object of the present invention can be also achieved by a second information reproducing method of reproducing record information from the above described information record medium such as a DVD or the like of the present invention. The second information reproducing method is provided with the processes of: detecting the partially replaced record information from the information record medium; extracting the identification information from the partially replaced record information detected by the detecting process; judging whether or not the identification information is extracted by the extracting process; applying the error correction to the partially replaced record information, which is detected by the detecting process, by use of the error correction code; and reproducing the record information on the basis of the partially replaced record information, to which the error correction is applied, only if the identification information is judged to be extracted by the judging process.
According to the second information reproducing method, at first in the detecting process, the partially replaced record information is detected from the information record medium. Then, in the extracting process, the identification information is extracted from the partially replaced record information. Then, in the judging process, it is judged whether or not the identification information is extracted. Then, in the error correction applying process, the error correction is applied to the partially replaced record information by use of the error correction code. Finally, in the reproducing process, only if the identification information is judged to be extracted, the record information is reproduced on the basis of the partially replaced record information.
Therefore, since the reproduction can be performed only when the identification information is detected, it is possible to protect the record information having no identification information (i.e., the illegally copied record information) from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded. Therefore, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
In one aspect of each of the first and second information reproducing methods of the present invention, the information record medium is further provided with sub-identification information recorded on the information record medium by adding the sub-identification information, which indicates that the record information is not illegally copied, to the record information in advance. The error correction code is recorded by adding the error correction code to the record information to which the sub-identification information is added to thereby generate the record information having the error correction code and the sub-identification information. Assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by the aforementioned expression (1) (i.e., M=f(N)). In the extracting process, the identification information and the sub-identification information are extracted from the partially replaced record information. In the judging process, it is judged whether or not the identification information is extracted, and it is judged whether or not the relationship is expressed by the expression (1). In the reproducing process, the record information is reproduced only if the identification information is judged to be extracted and the relationship is judged to be expressed by the expression (1).
According to this aspect, in the extracting process, the identification information and the sub-identification information are extracted from the partially replaced record information. Then, in the judging process, it is judged whether or not the identification information is extracted, and it is judged whether or not the relationship is expressed by the expression (1). Finally, in the reproducing process, only if the identification information is judged to be extracted and the relationship is judged to be expressed by the expression (1), the record information is reproduced.
Thus, since the reproducing operation is performed only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, at the time of reproduction, it is possible to more effectively protect the record information, which has been illegally recorded, from being reproduced.
In another aspect of each of the first and second information reproducing methods of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol. The part of the record information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other is replaced with the identification information.
According to this aspect, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the record information itself is not replaced with the identification information. Thus, the error correction ability with respect to the record information itself is not degraded.
The above object of the present invention can be also achieved by a first information generating apparatus for generating output information to be outputted. The first information generating apparatus is provided with: an error correcting code adding device for adding an error correction code, which is used for an error correction of the output information when the output information is outputted, to the output information to thereby generate the output information having the error correction code; and a replacing device for replacing a part of the output information having the error correction code, which is generated by the error correcting code adding device, with identification information indicating that the output information to be outputted is not illegally copied to thereby generate the partially replaced output information.
According to the first information generating apparatus of the present invention, by the error correcting code adding device, the error correction code is added to the output information, so that the output information having the error correction code is generated. Then, by the replacing device, the part of the output information having the error correction code is replaced with the identification information, so that the partially replaced output information is generated.
Thus, for example, when the generated partially replaced output information is recorded onto the information record medium such as a DVD or the like and then the output information is reproduced from the information record medium, by allowing the reproducing operation only when the identification information is detected, it is possible to protect the output information having no identification information (i.e., the illegally copied output information) from being illegally reproduced.
Moreover, since the part of the output information having the error correction code is replaced with the identification information after the error correction code is added, even if the identification information is detected and the output information is reproduced when the output information is reproduced for example, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus. Therefore, the information reproducing apparatus which can reproduce the output information only when the identification information is detected can protect the reproduction of the output information recorded by the information recording apparatus.
Furthermore, for example, assuming that the partially replaced output information is transmitted to another information reproducing apparatus and is reproduced thereby, if the reproducing operation is allowed only when the identification information is detected, even if the output information having no identification information is transmitted, its illegal reproduction can be protected.
Moreover, even if the identification information is detected and the output information is reproduced after the transmission, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus. Therefore, the information reproducing apparatus, which can reproduce the output information only when the identification information is detected, can protect the reproduction of the output information recorded by the information recording apparatus.
In one aspect of the first information generating apparatus of the present invention, the information generating apparatus is further provided with a sub-identification information adding device for adding sub-identification information, which indicates that the output information is not illegally copied, to the output information. The error correction code adding device adds the error correction code to the output information to which the sub-identification information is added to thereby generate the output-information having the error correction code and the sub-identification information. Assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by the expression (1) (i.e., M=f(N)).
According to this aspect, for example, when the output information is reproduced from the information record medium, by allowing the reproducing operation only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, in the reproducing apparatus for reproducing the output information, it is possible to more effectively protect the output information, which has been illegally recorded, from being reproduced.
In another aspect of the first information generating apparatus of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol. The replacing device replaces the part of the output information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other with the identification information.
According to this aspect, for example, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the output information itself at the time of reproducing the output information which has been recorded on the information record medium, is not replaced with the identification information. Thus, the error correction ability with respect to the output information itself is not degraded. Further, in the similar manner, at the time of reproducing the output information which has been transmitted, the error correction ability with respect to the output information itself is not degraded.
The above object of the present invention can be also achieved by a first information reproducing apparatus for reproducing record information from the above described information record medium of the present invention. The first information reproducing apparatus is provided with: a detecting device for detecting the partially replaced record information from the information record medium; an extracting device for extracting the identification information from the partially replaced record information detected by the detecting device; a judging device for judging whether or not the identification information is extracted by the extracting device; and a reproducing device for reproducing the record information by applying the error correction to the partially replaced record information, which is detected by the detecting device, by use of the error correction code only if the identification information is judged to be extracted by the judging device.
According to the first information reproducing apparatus, at first by the detecting device, the partially replaced record information is detected from the information record medium. Then, by the extracting device, the identification information is extracted from the partially replaced record information. Then, by the judging device, it is judged whether or not the identification information is extracted. Finally, by the reproducing device, only if the identification information is judged to be extracted, the record information is reproduced by applying the error correction to the partially replaced record information by use of the error correction code.
Therefore, since the reproduction can be performed only when the identification information is detected, it is possible to protect the record information having no identification information (i.e., the illegally copied record information) from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded. Therefore, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
The above object of the present invention can be also achieved by a second information reproducing apparatus for reproducing record information from the above described information record medium of the present invention. The second information reproducing apparatus is provided with: a detecting device for detecting the partially replaced record information from the information record medium; an extracting device for extracting the identification information from the partially replaced record information detected by the detecting device; a judging device for judging whether or not the identification information is extracted by the extracting device; an error correction applying device for applying the error correction to the partially replaced record information, which is detected by the detecting device, by use of the error correction code; and a reproducing device for reproducing the record information on the basis of the partially replaced record information, to which the error correction is applied, only if the identification information is judged to be extracted by the judging device.
Therefore, since the reproduction can be performed only when the identification information is detected, it is possible to protect the record information having no identification information (i.e., the illegally copied record information) from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded. Therefore, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
In one aspect of each of the first and second information reproducing apparatuses of the present invention, the information record medium is further provided with sub-identification information recorded on the information record medium by adding the sub-identification information, which indicates that the record information is not illegally copied, to the record information in advance. The error correction code is recorded by adding the error correction code to the record information to which the sub-identification information is added to thereby generate the record information having the error correction code and the sub-identification information. Assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by the expression (1) (i.e., M=f(N)). The extracting device extracts the identification information and the sub-identification information from the partially replaced record information. The judging device judges whether or not the identification information is extracted, and whether or not the relationship is expressed by the expression (1). The reproducing device reproduces the record information only if the identification information is judged to be extracted and the relationship is judged to be expressed by the expression (1).
According to this aspect, by the extracting process, the identification information and the sub-identification information are extracted from the partially replaced record information. Then, by the judging process, it is judged whether or not the identification information is extracted, and it is judged whether or not the relationship is expressed by the expression (1). Finally, by the reproducing process, only if the identification information is judged to be extracted and the relationship is judged to be expressed by the expression (1), the record information is reproduced.
Thus, since the reproducing operation is performed only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, at the time of reproduction, it is possible to more effectively protect the record information, which has been illegally recorded, from being reproduced.
In another aspect of each of the first and second information reproducing apparatuses of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol. The part of the record information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other is replaced with the identification information.
According to this aspect, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the record information itself is not replaced with the identification information. Thus, the error correction ability with respect to the record information itself is not degraded.
The above object of the present invention can be achieved by a second information record medium on and from which record information is recorded and reproduced provided with: an error correction code recorded on the information record medium by adding the error correction code, which is used for an error correction of the record information when the record information is reproduced, to the record information to thereby generate the record information having the error correction code; identification information recorded on the information record medium by replacing one part of the record information having the error correction code with the identification information indicating that the record information to be reproduced is not illegally copied to thereby generate the partially replaced record information; and position information recorded on the information record medium by replacing another part of the record information having the error correction code with the position information indicating a position of the identification information within the partially replaced record information.
According to the second information record medium of the present invention, by replacing the part of the record information having the error correction code with the identification information, the partially replaced record information is recorded. Thus, by allowing the reproduction only when the identification is detected at the time of reproducing the partially replaced record information form the information record medium, it is possible to protect the record information, which does not have the identification information (i.e., which has been illegally copied), from being illegally reproduced.
Further, since the part of the record information having the error correction code is replaced with the identification information, even if the identification information is detected and the record information is reproduced, the identification information is erased by the error correction at the time of reproduction. Thus, at the time of recording the reproduced record information by another information recording apparatus, the identification information is not recorded.
Thus, by allowing the reproduction of the record information only when the identification information is detected, it is possible to protect the record information recorded by this another information recording apparatus.
Furthermore, since another part of the record information having the error correction code is replaced with the position information indicating the position of the identification information, even if the replacement position of the identification information within the partially replaced record information is changed in order to prevent the illegal copy, it is possible to extract the identification information by using the position information as the clue. Thus, by changing the replacement position of the identification information, it is possible to prevent the identification information from being illegally read out before the error correction at the time of reproducing the record information.
In one aspect of the second information record medium of the present invention, the identification information is generated by rearranging each of codes constituting original identification information, which is set in advance and which indicates that the record information is not illegally copied.
According to this aspect, since the identification information is generated by rearranging the codes constituting the original identification information indicating the non-illegal copy, even if the identification information is read out before the error correction at the time of reproducing the record information, it is possible to prevent the original identification information from being recognized.
In this aspect, the identification information may be generated by rearranging the codes, which correspond to a plurality of error correction units for the error correction, simultaneously within the original identification information.
By constructing in this manner, since the rearrangement over the plurality of error correction units is performed, it is possible to prevent the leakage of the identification information more effectively at the time of reproducing the record information.
In another aspect of the second information record medium of the present invention, the partially replaced record information is generated by replacing one portion of the record information having the error correction code such that one identification information is included over a plurality of error correction units for the error correction.
According to this aspect, since one identification information is included over the plurality of error correction units, it is possible to prevent the leakage of the identification information even more effectively at the time of recording the record information.
In another aspect of the second information record medium of the present invention, the record information before adding the error correction code is enciphered by an enciphering process which is varied in correspondence with a time of enciphering, and a content of the enciphering process and version information indicating the time of enciphering are included in the identification information.
According to this aspect, since the content of the enciphering process and the time of enciphering are included in the version information, by selecting the content of the deciphering process for deciphering the enciphered information in accordance with the time of enciphering for each content of the enciphering process at the time of reproducing the record information, even if the content of one enciphering process is leaked at the time of reproduction, it is possible to decipher the enciphered data by use of another enciphering process so as to effectively prevent the illegal copy.
In this aspect, encipher key information indicating an encipher key used in the enciphering process may be included in the identification information.
By constructing in this manner, since the enciphered output information cannot be deciphered if the identification information cannot be obtained at the time of reproduction, it is possible to effectively prevent the illegal copy.
Further in this case, the encipher key information may be inserted in the identification information after the encipher key information is enciphered by an enciphering process which is set in advance.
By constructing in this manner, since the encipher key information for the enciphering process is further enciphered, it is very difficult to decipher the enciphered record information.
In another aspect of the second information record medium of the present invention, the partially replaced record information is generated by replacing one part of the record information having the error correction code with (i) the error correction code, which is used for an error correction of the identification information when the record information is reproduced, and (ii) the identification information.
According to this aspect, even if the identification information becomes erroneous at the time of reproduction, it is possible to correct this and thereby certainly recognize the identification information.
In another aspect of the second information record medium of the present invention, the information record medium further comprises sub-identification information recorded on the information record medium by adding the sub-identification information, which indicates that the record information is not illegally copied, to the record information in advance, the error correction code is recorded by adding the error correction code to the record information to which the sub-identification information is added to thereby generate the record information having the error correction code and the sub-identification information, and assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by a following expression (1).
M=f(N)xe2x80x83xe2x80x83(1)
According to this aspect, the output information having the error correction code and the sub-identification information is recorded on the information record medium, and that the sub-identification information M is a predetermined function of the identification information N.
Thus, for example, when the record information is reproduced from the information record medium, by allowing the reproducing operation only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, in the reproducing apparatus for reproducing the record information, it is possible to more effectively protect the record information, which has been illegally recorded, from being reproduced.
In another aspect of the second information record medium of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol, and one part of the record information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other is replaced with the identification information.
According to this aspect, for example, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the record information itself at the time of reproducing the record information which has been recorded on the information record medium, is not replaced with the identification information. Thus, the error correction ability with respect to the record information itself is not degraded.
The above object of the present invention can be also achieved by a second information generating apparatus for generating output information to be outputted, provided with: an error correcting code adding device for adding an error correction code, which is used for an error correction of the output information when the output information is outputted, to the output information to thereby generate the output information having the error correction code; and a replacing device for replacing one part of the output information having the error correction code, which is generated by the error correcting code adding device, with identification information indicating that the output information to be outputted is not illegally copied to thereby generate the partially replaced output information, and for replacing another part of the output information having the error correction code with position information indicating a position of the identification information within the partially replaced output information.
According to the second information generating apparatus of the present invention, by the error correcting code adding device, the error correction code is added to the output information, so that the output information having the error correction code is generated. Then, by the replacing device, one part of the output information having the error correction code is replaced with the identification information, so that the partially replaced output information is generated.
Thus, for example, when the generated partially replaced output information is recorded onto the information record medium such as a DVD or the like and then the output information is reproduced from the information record medium, by allowing the reproducing operation only when the identification information is detected, it is possible to protect the output information having no identification information (i.e., the illegally copied output information) from being illegally reproduced.
Moreover, since the part of the output information having the error correction code is replaced with the identification information after the error correction code is added, even if the identification information is detected and the output information is reproduced when the output information is reproduced for example, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus.
Therefore, the information reproducing apparatus which can reproduce the output information only when the identification information is detected can protect the reproduction of the output information recorded by the information recording apparatus.
Furthermore, for example, assuming that the partially replaced output information is transmitted to another information reproducing apparatus and is reproduced thereby, if the reproducing operation is allowed only when the identification information is detected, even if the output information having no identification information is transmitted, its illegal reproduction can be protected.
Moreover, even if the identification information is detected and the output information is reproduced after the transmission, the identification information is erased by the error correction at the time of the reproduction. Hence, the identification information is not recorded any longer when the reproduced output information is recorded by the information recording apparatus. Therefore, the information reproducing apparatus, which can reproduce the output information only when the identification information is detected, can protect the reproduction of the output information recorded by the information recording apparatus.
Furthermore, since another part of the record information having the error correction code is replaced with the position information indicating the position of the identification information, even if the replacement position of the identification information within the partially replaced output information is changed in order to prevent the illegal copy, it is possible to extract the identification information by using the position information as the clue. Thus, by changing the replacement position of the identification information, it is possible to prevent the identification information from being illegally read out before the error correction at the time of outputting the output information.
In one aspect of the second information generating apparatus of the present invention, the apparatus is further provided with a rearranging device for rearranging each of codes constituting original identification information, which is set in advance and which indicates that the output information is not illegally copied, to thereby generate the identification information, and the replacing device replaces one part of the output information having the error correction code with the identification information generated by the rearranging device, to thereby generate the partially replaced output information.
According to this aspect, since the identification information is generated by rearranging the codes constituting the original identification information indicating the non-illegal copy, even if the identification information is read out before the error correction at the time of outputting the output information, it is possible to prevent the original identification information from being recognized.
In this aspect, the rearranging device may rearrange the codes, which correspond to a plurality of error correction units for the error correction, simultaneously within the original identification information, to thereby generate the identification information.
By constructing in this manner, since the rearrangement over the plurality of error correction units is performed, it is possible to prevent the leakage of the identification information more effectively at the time of outputting the output information.
In another aspect of the second information generating apparatus of the present invention, the replacing device replaces one portion of the output information having the error correction code such that one identification information is included over a plurality of error correction units for the error correction.
According to this aspect, since one identification information is included over the plurality of error correction units, it is possible to prevent the leakage of the identification information even more effectively at the time of outputting the output information.
In another aspect of the second information generating apparatus of the present invention, the apparatus is further provided with an enciphering device for enciphering the output information before adding the error correction code by an enciphering process which is varied in correspondence with a time of enciphering, and a content of the enciphering process and version information indicating the time of enciphering are included in the identification information.
According to this aspect, since the content of the enciphering process and the time of enciphering are included in the version information, by selecting the content of the deciphering process for deciphering the enciphered information in accordance with the time of enciphering for each content of the enciphering process at the time of outputting the output information, even if the content of one enciphering process is leaked at the time of reproduction, it is possible to decipher the enciphered data by use of another enciphering process so as to effectively prevent the illegal copy.
In this aspect, encipher key information indicating an encipher key used in the enciphering process may be included in the identification information.
By constructing in this manner, since the enciphered output information cannot be deciphered if the identification information cannot be obtained at the time of outputting, it is possible to effectively prevent the illegal copy.
Further in this case further, the apparatus may be further provided with an encipher key inserting device for inserting the encipher key information into the identification information after enciphering the encipher key information by an enciphering process which is set in advance.
By constructing in this manner, since the encipher key information for the enciphering process is further enciphered, it is very difficult to decipher the enciphered record information.
In another aspect of the second information generating apparatus of the present invention, the replacing device replaces one part of the output information having the error correction code with (i) the error correction code, which is used for an error correction of the identification information when the output information is outputted, and (ii) the identification information, to thereby generate the partially replaced output information.
According to this aspect, even if the identification information becomes erroneous at the time of outputting, it is possible to correct this and thereby certainly recognize the identification information.
In another aspect of the second information generating apparatus of the present invention, the information generating apparatus further comprises a sub-identification information adding device for adding sub-identification information, which indicates that the output information is not illegally copied, to the output information, the error correction code adding device adds the error correction code to the output information to which the sub-identification information is added to thereby generate the output information having the error correction code and the sub-identification information, and assuming that M represents the sub-identification information and N represents the identification information, a relationship between the sub-identification information M and the identification information N is expressed on the basis of a predetermined function f by a following expression (1).
M=f(N)xe2x80x83xe2x80x83(1)
According to this aspect, for example, when the output information is reproduced from the information record medium, by allowing the reproducing operation only when both of the sub-identification information M and the identification information N are detected, even if either one of the sub-identification information M and the identification information N is obtained by some unjust or unfair method, another one of the sub-identification information M and the identification information N cannot be correctly obtained unless the function f is determined. Therefore, in the reproducing apparatus for reproducing the output information, it is possible to more effectively protect the output information, which has been illegally recorded, from being reproduced.
In another aspect of the second information generating apparatus of the present invention, the error correction code comprises an inner code inspection symbol and an outer code inspection symbol, and the replacing device replaces one part of the output information having the error correction code at a portion thereof where the inner code inspection symbol and the outer code inspection symbol overlap to each other with the identification information.
According to this aspect, for example, the inner code inspection symbol or the outer code inspection symbol used for the error correction of the output information itself at the time of reproducing the output information which has been recorded on the information record medium, is not replaced with the identification information. Thus, the error correction ability with respect to the output information itself is not degraded. Further, in the similar manner, at the time of reproducing the output information which has been transmitted, the error correction ability with respect to the output information itself is not degraded.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.